| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:36.25 | ROC Fall Invitational | 2025-11-22 |
| 100m Breaststroke | 1:36.91 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 100m Butterfly | 1:38.76 | Beast Cup 2026 | 2026-01-10 |
| 100m Freestyle | 1:15.93 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 200m Breaststroke | 3:29.96 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 200m Freestyle | 2:45.85 | Winter Swimfest 2026 | 2026-01-24 |
| 200m IM | 3:09.92 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 400m Freestyle | 6:17.82 | 2025 Rob Masson Memorial Distance Meet | 2025-11-15 |
| 400m IM | 7:27.55 | 2025 Rob Masson Memorial Distance Meet | 2025-11-15 |
| 50m Breaststroke | 44.79 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 50m Butterfly | 42.75 | 2026 OSHAC Durham Cup | 2026-01-31 |
| 50m Freestyle | 34.04 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
Marchlewicz, Quynh's top personal bests include 100m Backstroke (1:36.25), 100m Breaststroke (1:36.91), 100m Butterfly (1:38.76), 100m Freestyle (1:15.93), 200m Breaststroke (3:29.96).
Marchlewicz, Quynh swims for Oshawa Aquatic Club.
Marchlewicz, Quynh has competed in 9 meets.